Granular activated carbon has also shown to be an effective physical filtration medium in water treatment plants, and has the added benefit of providing water quality protection by adsorption of taste and odor compounds or chemical contaminants.

Prior to retrofitting an existing multimedia filter with granular activated carbon, or designing a new granular activated carbon filter, several practical considerations are necessary, including hydraulic requirements, filter on-stream time, and backwash water availability.activated carbon suppliers in china The properties of the granular activated carbon, such as adsorption performance, abrasion resistance and density must be considered as well. Additionally, the effective cost of converting the filter to granular activated carbon must be evaluated.

Backwashing requirements are another factor affecting how deep the granular activated carbon bed should be, particularly when retrofitting a multimedia filter. The filter design should allow for the optimal expansion while allowing several inches of clearance between the top of the expanded bed and the bottom of the backwash trough. Since the water velocity increases between the troughs, any granular activated carbon that is expanded to the level between the troughs will more than likely be washed out of the filter.

The mechanics of installing granular activated carbon in a filter retrofit or in a new filter are much the same as for installing sand and anthracite. A notable exception is that the filter and initial gravel/sand or underdrain/sand support must be disinfected prior to installing the granular activated carbon. This is because suitable disinfectants, such as chlorine, will rapidly react over granular activated carbon, leaving no disinfectant residual. activated carbon for gold mining A second variance is the granular activated carbon should be submerged for 24 hours prior to the final backwash before bringing the new filter into service. This soak time allows the air entrapped within the granular activated carbon pore structure to be removed and it allows the water to thoroughly wet the granular activated carbon internal surface.